Monitoring of Polio Antibody Levels in Different Regions of Chongqing under Existing Immunization Programs

Method

Four regions in Chongqing were randomly divided into two different vaccination schedules: 3IPV and 2IPV+bOPV, and tested for serum polio neutralizing antibodies 1~6 months after primary vaccination.Result For different sequential immunization schedules: The positive rates of poliovirus type I in the 2IPV+bOPV group and 3IPV group were 99.46%、100%, respectively(P＞0.05),and the median of antibody titer of 2IPV+bOPV group and 3IPV group were 2048 and 128, respectively (P<0.05); The positive rates of poliovirus type Ⅱ in the 2IPV+bOPV group and 3IPV group were 99.83%、100%, respectively(P＜0.05),and the median of antibody titer of 2IPV+bOPV group and 3IPV group were 96 and 192, respectively (P<0.05); The positive rates of poliovirus type Ⅲ in the 2IPV+bOPV group and 3IPV group were 99.46%、99.55%, respectively(P＞0.05),and the median of antibody titer of 2IPV+bOPV group and 3IPV group were 2048 and 256, respectively (P<0.05).Conclusion Different immunization schedules are one of the most important influencing factors.